With the advent of modern turbine engines, much consideration has been given to the development of engine components capable of withstanding mechanical and thermal stresses far in excess of those which were known in the past. Severe conditions including high velocities of rotation and high temperatures often cause excessive wear and premature failure of engine components.
Shaft seals are an integral component of the turbine engine, and are therefore, subjected to the same severe operating conditions. It has heretofore been known in the art to use a labyrinth seal. However, these seals have proven to exhibit high leakage rates and are therefore not desirable in many applications.
Another type of turbine engine shaft seal is a brush seal having bristles formed from numerous small diameter wires. A drawback to this type of seal is that the individual wires must maintain a spring temper to be effective. Such temper is often difficult to maintain at the high temperatures at which turbine engines operate.
Thus, a need exists for a shaft seal capable of operating in environments giving rise to severely degrading conditions. Such a seal should maintain its integrity even if it wears excessively in the presence of these conditions.